1. Field of the Invention
The present invention relates to a toner for use in a full color image forming apparatus.
2. Description of the Related Arts
Conventionally, full color image forming apparatuses such as full color copying machines, full color printers and the like form full color images using color toners such as cyan toner, magenta toner, and yellow toner in addition to black toner.
Various types of methods are used in full color image forming apparatuses. Among these methods it is typical that an electrostatic latent image is formed on the charged surface of a photosensitive member via optical exposure by a laser beam or the like, and said latent image is developed using specific toner selected among cyan, magenta, yellow, and black toners, said developed toner images being superimposed one upon another to produce a full color image.
In the aforesaid type of full color image forming apparatus, monochrome images are formed using only black toner.
Heretofore, identical binder resins have been used for color toners and black toners alike in the aforesaid full color image forming apparatus.
Black toner alone is frequently used when forming monochrome images rather than full color images. When black toner is formed using the same binder resin as is used for color toner and the black toner is frequently used alone, the black toner is rapidly fatigued in comparison to the other color toners. Furthermore, when black toner is formed using the same binder resin as is used for color toner, the gloss of the black portions of an image formed by said black toner is overly enhanced. Thus, when forming full color images, only the black portions are prominent due to over enhancement, such that there is discordance between said black portions and other portions formed by other color toners.